WO2003049540A1

WO2003049540A1 - Water dispersible granules containing benzoylphenylurea pesticides

Info

Publication number: WO2003049540A1
Application number: PCT/IL2002/000998
Authority: WO
Inventors: Avner Barazani
Original assignee: Makhteshim Chemical Works Ltd.
Priority date: 2001-12-12
Filing date: 2002-12-11
Publication date: 2003-06-19
Also published as: IL147063A0; AU2002358958A1

Abstract

A pesticidal composition in the form of a water dispersible granule which contains one or more benzoylphenyl urea compound as an active ingredient. The composition is prepared by abosrbing the active ingredient into an absorbent water dispersible granule.

Description

WATER DISPERSIBLE GRANULES CONTAINING BENZOYLPHENYLUREA PESTICI_DE_S

Field of the Invention

The present invention relates to the field of pesticidal compositions, particularly to water dispersible granules containing pesticidal active ingredients.

Background of the Invention

Much effort has been applied in the field of pest control in the development of formulation which are safer for the user and the environment. The most commonly used formulations for solid water insoluble pesticides are suspension concentrates and emulsion in water formulations, which are liquid formulations. Said formulations usually require the use of organic solvents and other additives, which may present a problem in term of user safety and environmental safety. Furthermore, there are additional risks associated with the handling of liquid formulations. Accordingly, different formulations have been developed to reduce the risks involved in handling said liquid formulations. One such formulation is the water dispersible granular (WDG) formulation which is a solid formulation that generally incorporates the active ingredient into a granule. These type of formulations present advantages in terms of storage as well as in terms of handling and toxicity. WDG formulations are commonly prepared by an extrusion process such as the process described in EP 321 527. However, it has been found that preparing WDG formulations by extrusion wherein the active ingredient is in the liquid results in granules with poor stability which tend to deteriorate upon storage. Thus, EP 633722 which is equivalent to U.S. 5,739,081 incorporated in its entirety herein by reference, describes a water dispersible granular formulation suitable for agricultural applications and a method for preparing said granules, according to which the active ingredient is in liquid form and absorbed into the granule, thus producing a stable WDG.

However, there are cases wherein formulations which are safer for the user and the environment demonstrate lower toxicity to the pest, hence a decrease in efficacy. EP 633,722 demonstrates that although the WDG formulations therein are safer and more convenient to handle, in some cases the efficacy of the WDG is lower than SC or EW formulations.

The group of pesticides known as benzoyl ureas, which includes ter alia, novaluron, lufenuron, hexaflumuron, triflumuron, diflubenzuron, chlorfluazuron and teflubenzuron are used as insect growth regulators (IGR). Said compounds are solid at ambient temperatures and have an extremely low water solubility. Accordingly, the commercial products containing said IGR's as active ingredients are commonly sold as suspension concentrates (SC) or emulsion in water (EW) formulations. Hence, the problems associated with liquid formulations in terms of toxicity, handling and storage, exist in this case as well.

There is therefore a long felt need to develop a pesticidal formulation of benzoyl ureas which has the advantages of WDG formulation with improved efficacy.

It is therefore a purpose of the present invention to provide a pesticidal composition in the form of a WDG with improved efficacy.

A further purpose of the present invention is to present a method for pest control wherein an improved WDG formulation is applied.

Other objects of the invention will become apparent as the description proceeds.

Summary of the Invention

The present invention provides a pesticidal composition in the form of a water dispersible granule (WDG) which contains one or more benzoylphenyl urea (BPU) compound as an active ingredient, wherein said composition is prepared by absorbing the active ingredient in liquid form or solution, into an absorbent water dispersible granule prepared from filler particles in a finely divided state and a dispersing agent. According to a further aspect of the present invention there is provided a method for pest control, comprising applying the presently described WDG composition to a plant or area in need of pest control.

Detailed Description of a Preferred Embodiment of the Invention

The following description is illustrative of embodiments of the invention. The following description is not to be construed as limiting, it being understood that the skilled person may carry out many obvious variations to the invention.

Throughout the description, percentages of components are by weight, unless specifically noted differently. The terms "benzoyl urea" and "benzoylphenyl urea" as used throughout the specification are synonymous.

It has surprisingly been found that WDG formulations containing one or more benzoylphenyl urea compounds as active ingredients, which are prepared according to the method claimed in EP 633 722 and the U.S. counter part U.S. 5,739,081, incorporated herein by reference, are more efficacious than other WDG formulations of BPU's. Furthermore, it has surprisingly been found that the WDG formulations of the present invention are more efficacious than suspension concentrate (SC) and emulsion concentrate (EC) formulations of BPU's. Hence, the present invention presents a WDG formulation which encompasses the advantages of WDG formulations in terms of safety, handling and storage with the advantages of EC and SC formulations in terms of efficacy.

According to an embodiment of the present invention there is provided a WDG formulation containing one or more BPU pesticidal compound. Non-limiting examples of BPU's suitable for the present invention are (common names) novaluron, lufenuron, hexaflumuron, triflumuron, diflubenzuron, chlorfluazuron, flufenoxuron, fluazuron, flucycloxuron, teflubenzuron and noviflumuron (also known by code name XDE 007). Said formulation containing 0.5% to 45% BPU, preferably 1% to 15%. The description of the present pesticidal composition shall now proceed in accordance with the method of preparation described in EP 633,722. The BPU in accordance with the present invention needs to be in a liquid state or formed into a liquid state, by for example dissolution in a suitable solvent or non-volatile compatible material, such as vegetable or mineral oils or in the form of a suspension or emulsion. The non-volatile compatible material may be surface active agent or adjuvant therefor. The term "liquid state" also refers to suspensions, emulsions and solutions of the active ingredient.

The BPU is preferably in a form in which it is miscible, dispersible or emulsifiable with water preferably by addition of suitable emulsifiers or by use of a suitable solvent or co- solvent. In practice it is found that EC formulations of the BPU with a reduced amount of the carrier organic solvent are suitable for absorption into the absorbent granules. It is within the scope of the present invention for the BPU to be rendered water miscible, dispersible or emulsifiable after it has been added to the absorbent granules. This can be achieved by pre-adding or post-adding suitable surfactants to the granules. The surfactants are such that if pre-blended with the BPU, the mixture is water miscible, dispersible or emulsifiable. By water miscible it is meant that the composition may be in the form of a fine emulsion, suspension or solution.

The WDG is prepared by absorbing the active ingredient in liquid form, into an absorbent water dispersible granule prepared from filler particles in a finely divided state and a dispersing agent.

The finely divided filler particles that are used to prepare the absorbent granules of this invention will normally be selected from inert mineral fillers. The particle size of the finely divided filler will depend upon the ultimate use of the granule. When used in spray tanks with conventional spray equipment the filler will need to be of a size to ensure that it passes freely through the spray nozzles without blockage. The preferred particle size will be less than 150 μm. The most preferred range will be 1-50 μm. The filler materials should adhere also be of a type that do not of themselves adhere and form agglomerates that will not redisperse readily. Accordingly, precipitated silica is not preferred but can be tolerated at low levels.

Suitable substances for use as the finely divided filler include mineral earths and clays such as bentonite, kaolin, attapulgite, diatomaceous earth, zeolites, calcium carbonate, talc, muscovite mica and manufactured materials such as precipitated silicas and silicates, fused sodium potassium, aluminum silicate (heat processed perlite) or organic materials such as coals, lignites and plastics. The fillers are preferably water insoluble. The finely divided filler itself may be absorbent as in the case of diatomaceous earth, attapulgite or zeolites but this is not essential.

Preferred materials include heat processed perlite, talc and muscovite mica, and combinations of such materials.

The absorbency of the granules is influenced by the degree of packing and the type of filers used. A mixture of different fillers can also be used.

The finely divided filler particles are water dispersible by including a dispersing agent. The amount of dispersing agent will vary from 1-30% w/w of the absorbent granule and more preferably 5-15% w/w of granule. Suitable dispersing or wetting agents include surface active agents and water soluble polymers, for example, lignosulphonate salts, polyacrylates and phosphate esters condensation products of formaldehyde, polyethylene glycol, and sugars. Suitable absorbent granules have been prepared with the following dispersing agent: "Morwet D425" (sodium naphthalene formaldehyde condensate ex Witco Corporation, USA) "Morwet EFW" Sulfated Alkyl Carboxylate and Alkyl Naphthalene Sulfonate—Sodium Salt "Tamol PP" (sodium salt of a phenolsulphonic acid condensate) "Reax 80N" (sodium lignosulphonate) "Wettol Dl" sodium alkylnaphthalene sulphonate (ex BASF). Generally the dispersing or wetting agents are anionic surfactants. Optionally, binding agents may be used wherein said agents are selected from a range of natural or synthetic gums, sugars, and polymers. Materials that do not swell rapidly upon hydration or become viscous are preferred.

Optionally, auxiliary agents such as surfactants and disintegrating agents may be added to modify the properties of the granules.

The materials comprising the preformed granule may be combined in any sequence and blended in a suitable blender and granulated using known methods and equipment for making granules.

To ensure satisfactory physical stability (and to avoid degradation of the loaded product) granules are preferably dried to a moisture content of not more than 1.0% w/w (as loss on drying). Temperature during drying is preferably controlled to a low temperature such as below 50°C.

Loading of the substance can take place in any suitable apparatus. The apparatus will deliver the BPU in liquid form to the agitated granules in such a manner that the liquid is taken up uniformly amongst all granules without damaging the granules. A suitable apparatus can therefore be a rotating cylinder, for example a Diosna universal mixer ex Dierks and Sohne GmbH & Co KG, a cone mixer with the liquid substance being delivered rapidly to the preformed granules via spray nozzles in a manner to distribute the substance over the surface of the absorbent granules as quickly as possible. The spray can be introduced through air atomising nozzles to ensure even spread of the liquid active substance the granules. Flat spray jets will in some cases be appropriate. Other means of delivering the liquid in the manner required can also be used.

It is preferred in loading the preformed granules with the liquid that a uniform loading per granule is achieved. Equilibration between unevenly loaded granules is believed to take place but this may take substantial periods of time. It is preferred to partially saturate the granules. It is preferably to load the granules to 60-90% and more preferably 70-85% of their capacity. Besides using the spraying techniques such as air atomising nozzles, it is possible to cool the liquid to increase its viscosity so that it does not flow into the granules so quickly. Agitation of the granules in the cooled liquid will lead to an even spread of the liquid over each granule and as the temperature rises absorption by each granule of its liquid coating and hence granules of uniform absorption.

Preferably the BPU will be mixed with an emulsifier to form an emulsifiable concentrate in a liquid form which can then be absorbed onto the preformed granule. Alternatively, the liquid substance can be dissolved in a suitable solvent, selected such that the solution is miscible with water, and then be absorbed onto the granule. The amount of solvent used in such a situation will be as low as possible in order to enable loading as high a concentration of the active substance into each granule as may be desired. If the liquid substance is miscible with water in its natural state, then it can be loaded onto the preformed granules without further modification.

The BPU may be converted to a water soluble form by the addition of a suitable emulsifier. It is possible for the surfactant and active material to be absorbed sequentially into the granules rather than as a premix. It is also possible for the granules to be prepared with the emulsifier present and the BPU is then subsequently absorbed into the granules. Dispersibility is still maintained in these variations.

Emulsifiers can be of the anionic, cationic or non-ionic type.

The preformed absorbent granules can be used to absorb liquid adjuvants which are substances designed to enhance the effect of the BPU. The adjuvant can be incorporated with the BPU in liquid form where the adjuvant and the substance are mutually compatible and remain so or alternatively a preformed granule can be loaded with BPU and then be subsequently loaded with an adjuvant. Alternatively, the BPU can be loaded into a first sample of the preformed granules and the adjuvant loaded into a second sample and these two samples added to water for spraying. Furthermore, the BPU in solid form can be used as the finely divided filler, as long as it is rendered miscible in water. The preformed granule containing the BPU can then be used to absorb an adjuvant which is an enhancer for the BPU's activity.

The method by which the granules are formed is not particularly critical. However the type of granulation technique used may affect the absorbency of the granules. The granulation technique described in application PCT/AU 88/00201 is particularly advantageous.

The present invention provides a method for pest control comprising treating an area in need of control with the presently claimed pesticidal composition. The present method may be applied for agricultural and horticultural purposes, ornamentals and non- agricultural purposes, e.g. public health and domestic use. Said method is effective for the control of pests which are sensitive to BPU's.

The present method is particularly effective for controlling insects of, ter alia, the orders Lepidoptera, Coleoptera, Homoptera, Heteroptera, Diptera, Thysanoptera, Orthoptera, Anoplura, Siphonaptera, Mallophaga, Thysanura, Isoptera, Psocoptera and Hymenoptera, as well as representatives of the order Acarina of the families Ixodidae, Argasidae, Tetranychidae and Dermanyssidae.

In addition said method is effective in controlling flies, e.g. Musca domestica, termites, cockroaches and mosquito larvae. The presently claimed method is also suitable for controlling plant-destructive feeding insects in ornamentals and crops of useful plants, especially in cotton (e.g. against Spodoptera littoralis and Heliothis virescens) and in fruit and vegetables (e.g. against Laspeyresia pomonella, Cydia pomonella, Lithocolletis blancardella, Stigmella malella, Adoxophyes orana, Psylla piri, Cryptophlebia leucotreta, phyllocnistis citrella, Cydia molesta, Anarsia lineatella, Leptinotarsa decemlineata and Epilachna varivestis), as well as for controlling several species of mites, e.g., oleivora. The present method is further effective for controlling ectoparasites such as Lucilia sericata, in domestic animals and productive livestock, e.g. by treating animals, cowsheds, barns, stables etc., and pastures.

According to a particular embodiment of the present method, the pesticidal composition is used to prepare a tank mix which is then applied via spraying to the area or crop needing treatment. The active ingredient concentration in the tank mix is adjusted to the particular application, depending on agricultural or non-agricultural application, the crop and the pest. Although various methods of application may be employed as the skilled artisan may appreciate, spraying is the preferred method of application.

The present method may also be applied in conjunction with other pest control agents, either in a mixture or by sequential application. Examples of suitable additional pesticides include: organophosphorus compounds, ' nitrophenols and derivatives thereof, formamidines, ureas, carbamates, pyrethroids, chlorinated hydrocarbons preparations.

Examples

The following is a glossary for terms used throughout the Examples: a.i.: active ingredient 10-EC: An emulsion concentrate containing 100 gr a.i./liter (equivalent to EC- 10).

75-WDG: A water dispersible granule formulation containing 75 gr a.i./Kg prepared according to prior-art methods. WDG-50: A water dispersible granule formulation containing 50 gr a.i./Kg prepared according to prior-art methods. SC-10: A suspension concentrate containing 100 gr a.i./liter.

WDG 7.5: A water dispersible granule formulation containing 75 gr a.i./Kg prepared according the present invention. Example 1: WDG formulation of novaluron

Novaluron (technical) 76.4

Perlite 460

Talc 105

Dispersant¹ 63

N,N-dimethyl amides of fatty acids 271

Emulsifier (nonionic)² 11

Emulsifier (anionic) 7.3

Residual moisture 6.2

= sodium lignosuphonate = calcium alkylbenzene sulphonate — Ethoxylated-propoxylated alkalylphenol (block copolymer)

Example 2: Comparative Example of Formulations

The comparative toxicity of three different novaluron formulations on developing stages of Bemisia tabaci was tested.

novaluron formulations No. of Pupation, in mg a.i./litre eggs %+SEM

- (Control) 607 85.0+1.6 a

10-EC

2 939 0.5+0.2 c

10-EC, AL*

2 888 0.3+0.3 c

5-EC. CH**

2 929 0.1+0.1 c

75-WDG

2 695 33.7±10.9 b

75-WDG

2 641 46.2+8.7 b

* AL and CH are different EC formulations. Cotton seedlings treated with 2 mg a.i./litre of each of the novaluron formulations were then exposed to whitefly females for 48-h oviposition. Effect on pupation was then determined. Means followed by the same letter do not differ significantly at P=0.05. The data clearly suggests that EC formulations showed similar potency on B. tabaci and were considerably more potent than the WDG formulations.

Example 3: Comparative Example of Formulations

The Potency of novaluron WDG-7.5 at 0.4 mg a.i./litre in comparison with novaluron EC- 10 and SC-10 on 3^rd-instar S. littoralis was tested

novaluron formulation No. of Larval mortality, % at LWG in mg a.i./litre L3 4 d 8d rel. to con.

- (Control) 60 . 5±3 a 5+3 a 100 a

EC-10 60 15±4 b 97±3 c 34±1 c

SC-10 60 3±3 a 60+11 b 55+7 b

WDG-7.5 60 93±3 c 98+2 c 27±7 cd

WDG-7.5 60 87+8 c 92+4 c 21±3 d

Castor bean leaves treated with 4 mg a.i./litre of each of the novaluron formulations, were exposed to 3^rd-instar S. littoralis (11+1 mg) for 4-day feeding and for additional 4 days on untreated leaves. Larval weight gain was determined at day 4 and larval mortality at day 4 and 8. Data are averages±SEM of 6 replicates of 10 larvae each. Within columns, means followed by the same letter do not differ significantly at P=0.05.

The data clearly demonstrates the strong knock down effect of the WDG formulation of the present invention, already at day 4, the WDG formulation was more potent than the EC and the SC formulations. However at day 8 the potency of the WDG formulations were similar to the EC formulation. All formulations were significantly more potent than the SC formulation. It seems that the WDG formulations act faster than the EC formulation.

Example 4: Comparative Example of Formulations Potency of WDG-7.5 at 0.1 mg a.i./liter in comparison with novaluron EC and SC formulations.

novaluron No. of Larval mortality, % at LWG formulation L3 4 d 8 d rel. to con.

- (Control) 60 0 a 0 a 100 a

EC-10 60 7+4 a 55±13 b 36+6 be

EC- 10, AL 60 0 a 40±15 b 46±6 b

SC-10 60 0 a 30±16 ab 53+9 b

WDG-7.5 60 55±20 b 92±5 c 24+2 c

WDG-7.5 60 58+18 b 97+2 c 23+1 c

Castor bean leaves treated with 0.1 mg a.i./litre of each of the novaluron formulations were exposed to 3^rd-instar S. littoralis (11+1 mg) for 4-day feeding and for additional 4 days on untreated leaves. Larval mortality was determined at day 4 and day 8. Larval weight gain (LWG) was determined at day 4. Average larval weight gain in the control is 125+8 mg. Data are averages±SEM of 6 replicates of 10 larvae each. Within columns, means followed by the same letter do not differ significantly at P=0.05.

Results: At day 4 and 8, both WDG formulations at O.Olmg a.i./litre were more potent than the EC and the SC formulations. WDG formulations resulted also in stronger suppression of larval weight gain at day 4. Example 5: Comparative Example

Potency of WDG-7.5 at 0.1 mg a.i./litre in comparison with novaluron EC and SC formulations on l^st-instar Helicoverpa armigera

novaluron No. of Larval mortality, formulation LI %+SEM

(Control) 50 0 a

EC-10 50 79+3 be SC-10 50 67+6 b

WDG-7.5 50 88+6 c

WDG-7.5 50 91±5 c

Cotton leaves dipped in 0.1 mg a.i./litre of each of novaluron formulations were exposed to l^st-instar H. armigera. Effect on larval mortality was determined 5 days after start of assay. Data are averages of 5 replicates of 10 larvae (0-12 h after hatching) each. Means followed by the same letter do not differ significantly at P=0.05.

Results: Both WDG formulations were more potent than the EC and SC formulations.

Example 6: Comparative Example

Potency of WDG-7.5 in comparison with Rimon EC-10 on 3 -instar S. littoralis.

novaluron formulation No. of Larval mortality, % at LWG in mg, a.i./litre L3 4 d 8 d rel. to con

- (Control) 60 0 a 0 a 100 a

EC-10 0.2 60 3+3 a 90+4 b 42+3 b

WDG-7.5

0.1 60 48±14 b 92±4b 36+3 be

0.2 60 63+13 b 97+2 b 29+9 bed

WDG-7.5

0.1 60 68±3b 98+2 b 20+3 d

0.2 60 77+10 b 100 b 32±2c Castor bean leaves treated with 0.1 and/or 0.2 mg a.i./litre of each of the novaluron formulation were exposed to 3^rd-instar S. littoralis (11+1 mg) for 4-day feeding and for additional 4 days on untreated leaves. Larval weight gain (LWG) was determined at day 4 and larval mortality at day 4 and 8. Average LWG in the control is 63+4 mg. Data are average+SEM of 6 replicated of 10 larvae each. Within columns, means followed by the same letter do not differ significantly at P=0.05.

Results: At day 4 both WDG formulations (0.1 and 0.2 mg a.i./litre) were more potent than the EC formulation (0.2 mg a.i./litre). The stronger suppression of LWG obtained with the WDG as compared to the EC formulation may result from faster activity.

While embodiments of the invention have been described by way of illustration, it will be apparent that the invention may be carried out with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of the claims.

Claims

1. A pesticidal composition in the form of a water dispersible granule which contains one or more benzoylphenyl urea (BPU) compound as an active ingredient, wherein said composition is prepared by absorbing the active ingredient in liquid form or solution, into an absorbent water dispersible granule.

2. A composition according to claim 1 comprising 0.5% to 45% active ingredient.

3. A composition according to claim 2 comprising 1% to 15% active ingredient.

4. A composition according to claim 1 wherein the active ingredient is selected from among a group comprising of novaluron, lufenuron, hexaflumuron, triflumuron, diflubenzuron, chlorfluazuron, flufenoxuron, fluazuron, flucycloxuron, teflubenzuron and noviflumuron.

5. A composition according to claim 1 wherein the water dispersible granule is prepared from filler particles in a finely divided state and a dispersing agent.

6. A method for pest control, comprising applying a WDG composition as described in claim 1 to a plant or area in need of pest control.

7. A method according to claim 6 wherein for pest control in agriculture, horticulture, ornamentals and non-agricultural purposes.

8. A method according to claim 6 for controlling ectoparasites in domestic animals and productive livestock and pastures.

9. A method according to claim 6 for controlling mosquitoes and mosquito larva.

10. A water dispersible granule composition as herein described and exemplified. -lo¬

ll . A pest control method as herein described and exemplified.